Electric switch



Parental Maf. 16, 1926.

JOSEPH S. THOMPSON, OF ASAN FRANCISCOQCALIFORNIA.

ELECTRIC ^sWITcH. .y

Application iled May 11, 1925. Serial No. 29,282.

To all whom t may concern v Be it known that I, JOSEPH S. THOMPSON, a cit-izen of the United States, residing in the city and county of San Francisco, State of California, have invented a c ertain'new and useful Electric Switch, of which the following is a specification.

The invention relates to electric switches. More particularly it relates to disconnecting switches of the knife or blade type, and has for its object the provision of an improved' switchof this character whereby a complete and efiicient Contact may be secured between the blade and the switch contacts.

An object of my invention is to provide contacting means arranged to engage between the forks of a bifurcated switch blade, or a blade having two spaced plates, which means are self-aligning so as to secure a complete contact.

Another object. of my invention is to provide a switch having contactingfmeans of the character described which means are compressible so that when the switch is closed, said means will`- tightly hold the blade in its closed position as well as clamp-the forksof said blade .between itself and the adjacent contacts to secure a complete and efiicient contact.

The invention possesses other advantageous features, some of which with the foregoing will be set forth at length in the following description, where I shall outline in full that form of the invent-ion which I have selected for illustration in the drawings accompanying and forming part of the present specification. shown one form of device embodying my invention, but it is to be understood that I,

do not limit myself to such form, since the invention as set forth in the claims may be embodied in a plurality of other forms.

In the drawings:

'-l Figure 1 "s a vertical sectional view of 'a' switch embodying my invention; and

Fig. 2 is a perspective view with parts shown in section illustrating` details shown in Fig. 1.

Referring to the drawings in which 1 indicates a switch base, which is provided with a 'pair of contactsor shoes 2, 2. :The contact 2 is resiliently supported by a spring 3 within an extension or housing 4 formed on the base 1 and is clamped or secured to said base by means of a bolt 5 as shown. The

contact 2 is supported in a similar manner In said drawings I havei bycorresponding parts which are given similar' reference numerals primed. Said contacts 2,2 are` electrically connected with the base 1 by fiexible conductors 6, 6 tively. It is of course understood that the base is of conducting material adapted to be mounted on an insulating panel. Intermediate the contacts 2, 2 is positioned my im;

proved contact element which consists of mi"v two plates 7, 8. These plates are secured to the base 1 by the bolt 5, which passes through an enlarged opening near the'base '3 of the same, as best shown in Fig. 2, so as to. permit a limited vertical movement ofthe plates thereon for adjusting or self-aligning purposes, readily understood. The plates therefore have a bodily movement which insuresI par in a manner allelism and therefore complete surface contact. The plates 7, 8 are each secured at their bases by similar members 9 to :flexible conductors` 11, 12 respectively, these conductors also being secured to the base 1 in the same manner as conductors 6, 6 are. their upper ends, the plates 7, 8 are' respectively provided with right and left hand interlocking projections 13, 14 which while permitting the blades to move toward each other, limit Between the plates 7, 8.are two steel springs 15, 16 which are bent to react against eachA other. These springs are held on the base by the boltl 5, and their lower ends are re-r tained in a groove 17 in the base 1. Their 90 upper ends engage the inner surfaces of plates 7, 8 and tend to urge the same apart, thus forming a compressible contact element between the shoes 2, 2. With my invention,

I employ a switch blade having two plates understood that the l 18, 19. It-is of course switch blade may consist of two spaced platesor it may consist of a single bifurcated blade and it is to be understood that the term bifurcatedis intended to apply to either type of construction. Preferably the lower edges of the switch blade are rounded as shown. Likewise, the interlocking projections 13, 14' are rounded, so that the the distance theymay separate. 95

respec- 60 as well as an axial 70A/ switch blade may readily pass over the same. When the switch is closed, as shownin Fig.

contacts, and a contact element intermediate The plates 18, 19 are also in complete contact with shoes 2, 2, due `to their resilient "mounting It is of course understood that the several contacting surfaces have been machined to secure the best contact.

What I claim and desire to secure by Unlted States Letters Patent is:

., L Inan electric switch, a pair of spaced said spaced contacts comprising two adjacent;` plates, means between the same normally urging said plates apart and means limiting the separation of the same said plates being supported to permit a limited vertical and horizontal movement.

2. An electrlc switch comprising a bifurcated switch blade, spaced contacts adapted lto make contact with the outer surfaces of said blade and means for making contact between the forks of said blade comprising two blades having interlocking projections permitting a limited separation of said blades and resilient means tending to sepai rate said blades.

3. An electric switch comprising a bifurcated switch blade, spaced contacts adapted to make Contact with'the outer surfaces of said blade and contacting means adapted to engage between the forks of said blade comprising two plates loosely supported at their' loweru parts to permit self-alignment, said plates having interlocking means at their upper ends to permit a limited separation of said blades and resilient means between said plates normally urging the same apart.

4. An electric switch comprising a bifurcated switch blade, `resiliently supported Levens@ ff spaced contacts adapted to make contact with the outer surfaces of said blade and contacting means adapted to engage between the forks of said blade comprising two plates loosely supported at their lower parts to permit self-alignment, said plates having interlocking means at their upper ends to permit a limited separation of said blades and resilient means between said plates normally urging the same apart.

5. An electric switch comprising a bifur cated switch blade, resilient mounted spaced contact-s adapted to engage the outer surfaces of said blade, and resilient contact means adapted to urge the forks of said blade against; the adjacent contact said means being loosely supported to permit self-alignment.

6. A11 electric switch comprising a bifurcated switch blade, spaced contacts adapted to make contact with the outer surfaces of said blade and a compressible contact elemy hand.

JOSEPH S. THOMPSON. 

